Double PWHT on CS Piping 2

[rajarathinam285]

WHETHER PWHT IS PERMITTED TO DO 2nd TIME IN CASE OF DEFECTIVE RECORDER/POWER FAILURE.

 

[metengr]

If you are not in compliance with the original PWHT, you need to perform it for a second time. Is the weld region impact qualified?

 

[weldstan]

Per ASME IX, for most welds tme at temperature is npot an essential variable; however, for welds subject to impact testing or for making corrosion resistant overlays or hard surfacing applications, it is.

 

[EdStainless]

But proving that you did not exceed the correct temp the first time could be a trick.
I would have everyone agree on the qualification details before I proceeded.

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Plymouth Tube

 

[rajarathinam285]

THE MATERIAL IS API 5L GR.B AND IT IS NOT IMPACT TESTED.THE SERVICE IS NORMAL FLUID(NO H2S/HYDRO CARBON SERVICE).THE PQR HAS BEEN QUALIFIED FOR SINGLE PWHT CYCLE.IF PWHT IS REPEATED WILL YIELD STRENGTH BE REDUCED?

 

[metengr]

No. This material is very forgiving. The yield strength will not be reduced by a repeated PWHT cycle following the correct parameters for time at temperature.